阅读说明：本技术 用于地外天体着陆的测距测速敏感器闭环验证系统及方法 (Distance and speed measuring sensor closed-loop verification system and method for extraterrestrial celestial body landing ) 是由 刘旺旺 赵宇 王晓磊 徐李佳 王云鹏 郝策 李茂登 陈尧 周益 张琳 于 2021-09-17 设计创作，主要内容包括：用于地外天体着陆的测距测速敏感器闭环验证系统及方法,系统包括星端产品和地面测试设备两部分,其中,星端产品包括星载计算机、测距测速敏感器,地面测试设备包括遥控遥测计算机、地面动力学参数设置计算机、地面动力学测试设备和测距测速敏感器回波模拟器。由测距测速敏感器回波模拟器根据收到的地面动力学测试设备发送的测距测速模拟测量值及其有效性,测距测速敏感器发送的同步控制信号、参考基准时钟信号、射频发射信号和模拟波束号及波形控制字等信息,输出所需波束的射频回波信号,经测距测速敏感器采集输出测距测速信息并发送给星载计算机处理,实现地外天体着陆过程测距测速修正功能和性能的试验室环境下硬件在回路闭环验证。(The system comprises a star-end product and ground test equipment, wherein the star-end product comprises a star-mounted computer and a distance and speed measuring sensor, and the ground test equipment comprises a remote control and remote measurement computer, a ground dynamics parameter setting computer, ground dynamics test equipment and a distance and speed measuring sensor echo simulator. And outputting a radio frequency echo signal of a required wave beam by the echo simulator of the distance and speed measuring sensor according to the received distance and speed measuring simulation measurement value and effectiveness thereof sent by the ground dynamics testing equipment, a synchronous control signal, a reference clock signal, a radio frequency emission signal, a simulation wave beam number, a waveform control word and other information sent by the distance and speed measuring sensor, acquiring and outputting distance and speed measuring information by the distance and speed measuring sensor and sending the distance and speed measuring information to a spaceborne computer for processing, thereby realizing the verification of the closed loop of the hardware under the laboratory environment with the distance and speed measuring correction function and performance in the landing process of the extraterrestrial celestial body.)

1. A range finding speed measuring sensor closed loop verification system for extraterrestrial celestial body lands, its characterized in that: including star year computer, range finding speed sensor, remote control telemetering measurement computer, ground dynamics parameter setting computer, ground dynamics test equipment and range finding speed sensor echo simulator, wherein:

an on-board computer: controlling the distance and speed measuring sensor to be in a working state, acquiring distance and speed measuring information from the distance and speed measuring sensor, sending the distance and speed measuring information to a remote control and remote measuring computer through on-satellite remote measurement, and determining the distance calibration value and the speed calibration value of each wave beam of the distance and speed measuring sensor through comparison with an initial measurement value set by a ground dynamics parameter setting computer; receiving initial position, speed, attitude angle, attitude angular speed and satellite time information of a detector sent by a remote control and remote measurement computer through a remote control command, forming guidance control command information and sending the guidance control command information to ground dynamics testing equipment, acquiring simulated measurement data of an inertia measurement unit provided by the ground dynamics testing equipment, and finishing on-satellite inertial navigation recursion; when the height of the detector from the surface of the extraterrestrial celestial body is smaller than the height allowed to be introduced by the distance and speed measuring sensor, obtaining the distance and speed measuring measured value and the relative measuring time information of the distance and speed measuring sensor in each control period, completing the correction of inertial navigation recursion data in the same control period, and driving ground dynamics testing equipment to complete the state updating of a detector dynamics model;

distance measuring and speed measuring sensors: sending an analog beam number and a waveform control word, a radio frequency emission signal, a reference clock signal and a synchronous control signal to a ranging and speed measuring sensor echo simulator; receiving a radio frequency echo signal from an echo simulator of the distance and speed measuring sensor, obtaining a current distance and speed measuring measured value and relative measuring time information and feeding back the current distance and speed measuring measured value and relative measuring time information to the spaceborne computer;

remote control and remote measurement computer: sending a remote control instruction to the satellite borne computer, and setting a closed loop test initial state of the satellite borne computer; receiving and displaying telemetering information of the satellite-borne computer;

a ground dynamics parameter setting computer: setting initial measurement values of the distance and the speed of the distance and speed measuring sensor; the initial measurement value can be data of the distance and speed measuring sensor during normal work, and can also be fault data of the distance and speed measuring sensor when the related wave beam is in fault output with a constant value, output with random or constant error and unavailable output;

ground dynamics test equipment: sending the initial measurement values of the distance and the speed of the distance and speed measuring sensor to an echo simulator of the distance and speed measuring sensor; driving and updating state information of a detector dynamic model according to guidance control instruction information sent by the satellite-borne computer, simulating and generating measurement information of a detector inertia measurement unit for the satellite-borne computer to collect, and completing satellite-ground time synchronization; meanwhile, when the height of the detector from the surface of the extraterrestrial celestial body is smaller than the height allowed to be introduced by the distance and speed measuring sensor, generating a distance and speed measuring simulation measured value in real time and sending the distance and speed measuring simulation measured value to the distance and speed measuring sensor echo simulator for use;

distance measuring and speed measuring sensor echo simulator: forming a radio frequency echo signal by using the initial measurement values of the distance and the speed of the distance and speed measuring sensor for the distance and speed measuring sensor to collect, and calibrating and compensating the distance, speed and telemetering information of the distance and speed measuring sensor by using the distance calibration value and the speed calibration value of each wave beam of the distance and speed measuring sensor so that the difference between the measurement result of the distance and speed measuring sensor and the initial measurement values of the distance and the speed provided by the ground dynamics test equipment meets the measurement error requirement; when closed loop test is verified, point target data with an initial value of 0 is generated, after the height of a detector from the surface of the extraterrestrial celestial body is smaller than the height allowed to be introduced by the distance measurement and speed measurement sensor, distance measurement and speed measurement analog measurement values sent by ground dynamics test equipment are received, the distance and speed values of each wave beam are analyzed, converted and updated, meanwhile, frequency conversion and modulation processing are carried out on received analog wave beam numbers, wave form control words, radio frequency emission signals and reference clock signals, echo data are calculated in real time according to corresponding distance delay, point target echo modulation data containing the echo characteristics of the extraterrestrial body surface in the current period are generated, and after synchronous control signals are received, radio frequency echo signals of required wave beams are output to the distance measurement and speed measurement sensor in real time.

2. The system and the method for verifying the closed loop of the distance measuring and speed measuring sensor for the landing of the extraterrestrial celestial body as claimed in claim 1, wherein: and the spaceborne computer and the distance and speed measuring sensor are communicated by adopting an RS422 serial port.

3. The system and the method for verifying the closed loop of the distance measuring and speed measuring sensor for the landing of the extraterrestrial celestial body as claimed in claim 1, wherein: and the on-board computer corrects the inertial navigation recurrence data by adopting an inertial navigation and distance and speed measurement information robust fusion algorithm.

4. The system and the method for verifying the closed loop of the distance measuring and speed measuring sensor for the landing of the extraterrestrial celestial body as claimed in claim 1, wherein: and the distance measuring and speed measuring sensor echo simulator is communicated with the ground dynamics testing equipment by adopting a UDP network protocol.

5. The closed-loop verification method of the distance measurement and speed measurement sensor for the landing of the extraterrestrial celestial body is characterized by comprising the following steps of: the method comprises a calibration step and a normal test step,

the calibration process comprises the following steps:

1) the ground dynamics parameter setting computer sets the distance and the speed of the distance and speed measuring sensor sent by the ground dynamics testing equipment as fixed measurement values;

2) the remote control and remote measurement computer injects an instruction into the spaceborne computer to enable the distance and speed measurement sensor to be in a full working state, then sends a single access instruction to obtain distance and speed measurement and remote measurement information, and determines the distance and speed calibration value of each wave beam by comparing the distance and speed measurement information with the fixed measurement value set by the ground dynamics parameter setting computer;

3) the distance and speed values are calibrated and compensated through the ranging and speed measuring sensor echo simulator, so that the difference between the measuring result of the ranging and speed measuring sensor and the distance and speed values provided by the ground dynamics testing equipment meets the requirement of measuring errors, and the ranging and speed measuring sensor echo simulator is calibrated;

the normal testing process comprises the following steps:

1) the satellite-borne computer starts operation according to the initial position, speed, attitude angle, attitude angular speed and satellite hour instruction information injected by the remote control and remote measurement computer, and sends the remote measurement information to the remote control and remote measurement computer for display; the ground dynamics equipment starts the updating of ground dynamics according to the set initial position, speed, attitude angle, attitude angular speed and satellite-hour information, and completes satellite-ground time synchronization; the ground dynamics test equipment simulates and generates the measurement information of the inertia measurement unit for the satellite-borne computer to collect according to the detector state information of the dynamics simulation; when the height of the detector from the surface of the extraterrestrial celestial body is smaller than the height allowed to be introduced by the distance and speed measuring sensor, starting to send the distance and speed measuring simulation measured value and the effectiveness thereof to the distance and speed measuring sensor echo simulator for use in real time;

2) the method comprises the steps that a satellite-borne computer obtains measurement data of an inertial measurement unit to finish satellite-borne inertial navigation recursion, when the height of a detector from the surface of an extraterrestrial celestial body is smaller than the height allowed to be introduced by a distance and speed measurement sensor, distance measurement, speed measurement value and effectiveness and relative measurement time information of the distance and speed measurement sensor are obtained in each control period, and correction of the inertial navigation recursion data is finished in the same control period; simultaneously, the satellite-borne computer sends a guidance control instruction to the ground dynamics testing equipment to drive the ground detector dynamics model;

3) the distance and speed measuring sensor echo simulator works in a point target mode, after the operation is started, the echo simulator always plays back point target data with an initial value of 0, after the height of the detector from the surface of the extraterrestrial celestial body is smaller than the height allowed to be introduced by the distance and speed measuring sensor, the ground dynamics testing equipment sends a distance and speed measuring analog value and the effectiveness thereof to the echo simulator, and the echo simulator analyzes, converts and updates the distance and speed value of each wave beam; simultaneously, carrying out frequency conversion and modulation processing on the received analog wave beam number and waveform control words, radio frequency emission signals and reference clock signals sent by the distance and speed measuring sensor, calculating echo data in real time according to corresponding distance delay, generating point target echo modulation data with the echo characteristics of the surface of the extraterrestrial celestial body in the current period, and outputting radio frequency echo signals of required wave beams to the distance and speed measuring sensor in real time after receiving synchronous control signals of the distance and speed measuring sensor;

4) the distance and speed measuring sensor acquires and processes the received radio frequency echo signal sent by the echo simulator to obtain the current distance and speed measuring information, and returns the distance and speed measuring information obtained by processing when the spaceborne computer sends a data fetching instruction;

5) the ground dynamics test equipment receives guidance control instruction information of the spaceborne computer, realizes driving of a digital model of an execution mechanism, generates force and moment information for driving a dynamic body of the detector, realizes real-time updating of state information of the dynamically simulated detector, and further simulates and generates measurement information of an inertia measurement unit and distance and speed measurement simulation values and effectiveness information of the distance and speed measurement simulation values sent to an echo simulator of the distance and speed measurement sensor according to measurement characteristics and error characteristics of the inertia measurement unit and the distance and speed measurement sensor.

6) And repeating the steps 1) to 5), and carrying out continuous hardware-in-loop closed-loop test on the performance of the speed and distance measuring sensor until the test requirements are met.

6. The closed-loop verification method of the distance measuring and speed measuring sensor for the landing of the extraterrestrial celestial body as claimed in claim 5, wherein the closed-loop verification method comprises the following steps: if the distance measurement and speed measurement fault closed-loop test is carried out, the relevant wave beams of the distance measurement and speed measurement sensor are set to be a constant fault output, a random or constant error output and an unavailable output through the ground dynamics parameter setting computer and are sent to the echo simulator through the ground dynamics test equipment, and the echo simulator outputs a radio frequency echo signal with a fault according to the set output for the distance measurement and speed measurement sensor to collect.

7. The closed-loop verification method of the distance measuring and speed measuring sensor for the landing of the extraterrestrial celestial body as claimed in claim 5, wherein the closed-loop verification method comprises the following steps: the data refresh rate of the radio frequency echo signal is not less than 20Hz, and the time delay is not more than 3 ms.

8. The closed-loop verification method of the distance measuring and speed measuring sensor for the landing of the extraterrestrial celestial body as claimed in claim 5, wherein the closed-loop verification method comprises the following steps: and the spaceborne computer and the distance and speed measuring sensor are communicated by adopting an RS422 serial port.

9. The closed-loop verification method of the distance measuring and speed measuring sensor for the landing of the extraterrestrial celestial body as claimed in claim 5, wherein the closed-loop verification method comprises the following steps: and the on-board computer corrects the inertial navigation recurrence data by adopting an inertial navigation and distance and speed measurement information robust fusion algorithm.

10. The closed-loop verification method of the distance measuring and speed measuring sensor for the landing of the extraterrestrial celestial body as claimed in claim 5, wherein the closed-loop verification method comprises the following steps: and the distance measuring and speed measuring sensor echo simulator is communicated with the ground dynamics testing equipment by adopting a UDP network protocol.

Technical Field

The invention belongs to the technical field of spacecraft ground test verification, and relates to a distance and speed measuring sensor closed-loop verification system and method for extraterrestrial celestial body landing.

Background

In the process of landing extraterrestrial celestial bodies, due to the performance limit of the inertial measurement unit, the error accumulation effect of navigation and the uncertainty of a landing area, the safe landing of the detector is difficult to guarantee by singly relying on autonomous inertial navigation recursion. Therefore, a distance-measuring and speed-measuring sensor is usually required to be configured, the relative position and speed information of the detector relative to the surface of the extraterrestrial celestial body are measured at the landing end, and the information is sent to the spaceborne computer to correct the inertial navigation recurrence data, so that the navigation precision is improved, and the landing safety is ensured.

In order to ensure that the functions and the performances of the distance and speed measuring sensor in the landing process meet the use requirements, a large amount of test verification needs to be carried out on the distance and speed measuring sensor on the ground. Usually, the functional performance of the distance and speed measuring sensor is verified mainly through an outfield crane test, an airborne hanging test and the like. However, due to the limitations of the flying height, speed, attitude angle and the like of the aircraft in the test process, the landing trajectory and attitude characteristics of the detector in the extraterrestrial celestial body landing process cannot be completely simulated through the external field test, and the external field test usually consumes a large amount of manpower, financial resources and material resources. Therefore, the echo simulator simulates and outputs the radio-frequency echo signal received by the distance and speed measuring sensor in the landing process of the detector under the laboratory environment, and the distance and speed measuring sensor receives and processes the echo signal to output distance and speed measuring information, so that the functional performance verification is an effective technical means.

At present, the research on the echo simulator of the distance and speed measuring sensor is relatively extensive and mature in China. The patent "a radar target simulator for Ku wave band full phase reference" (application number: CN201310737577.6) discloses a radar target simulator for Ku wave band full phase reference, which explains the hardware composition of the simulator and the implementation mode of an echo simulation signal of Ku wave band full phase reference, and provides a foundation for completing the performance test of Ku wave band radar equipment. The patent 'radar target echo simulation method and system' (application number: CN201711250219.7) discloses a radar target echo simulation method and system for performing echo simulation based on a variable RCS value, which can vividly and accurately simulate the effect of an actual road target when the actual road target is irradiated by a radar and improve the accuracy of a radar test result. The patent "speed measuring and ranging radar echo simulator and simulation method for surface target" (application number: CN201610027219.X) discloses a speed measuring and ranging radar echo simulator and simulation method for surface target, and explains the hardware composition of the simulator and the realization way of simulating echo signal by surface target. These patents mainly relate to the design and implementation level of an echo simulator, and do not relate to the specific use of the simulator and the closed-loop verification of the distance measurement and speed measurement correction functions of a sensor in a system environment.

Disclosure of Invention

The technical problem solved by the invention is as follows: the closed-loop test and verification system is composed of a star-end product and ground test equipment, and the closed-loop test and verification system realizes the time sequence matching of a star-mounted computer and a distance and speed measuring sensor in a laboratory environment and hardware in loop closed-loop verification of distance and speed measuring correction function and performance in the landing process of the extraterrestrial celestial body.

The technical solution of the invention is as follows: a distance measurement and speed measurement sensor closed-loop verification system for the landing of extraterrestrial celestial bodies comprises a satellite-borne computer, a distance measurement and speed measurement sensor, a remote control and remote measurement computer, a ground dynamics parameter setting computer, ground dynamics testing equipment and a distance measurement and speed measurement sensor echo simulator, wherein:

an on-board computer: controlling the distance and speed measuring sensor to be in a working state, acquiring distance and speed measuring information from the distance and speed measuring sensor, sending the distance and speed measuring information to a remote control and remote measuring computer through on-satellite remote measurement, and determining the distance calibration value and the speed calibration value of each wave beam of the distance and speed measuring sensor through comparison with an initial measurement value set by a ground dynamics parameter setting computer; receiving initial position, speed, attitude angle, attitude angular speed, satellite hour and other information of the detector sent by a remote control and remote measurement computer through a remote control command, forming guidance control command information and sending the guidance control command information to ground dynamics testing equipment, acquiring simulated measurement data of an inertia measurement unit provided by the ground dynamics testing equipment, and finishing on-satellite inertial navigation recursion; when the height of the detector from the surface of the extraterrestrial celestial body is smaller than the height allowed to be introduced by the distance and speed measuring sensor, obtaining the distance and speed measuring measured value and the relative measuring time information of the distance and speed measuring sensor in each control period, completing the correction of inertial navigation recursion data in the same control period, and driving ground dynamics testing equipment to complete the state updating of a detector dynamics model;

distance measuring and speed measuring sensors: sending an analog beam number and a waveform control word, a radio frequency emission signal, a reference clock signal and a synchronous control signal to a ranging and speed measuring sensor echo simulator; receiving a radio frequency echo signal from an echo simulator of the distance and speed measuring sensor, obtaining a current distance and speed measuring measured value and relative measuring time information and feeding back the current distance and speed measuring measured value and relative measuring time information to the spaceborne computer;

remote control and remote measurement computer: sending a remote control instruction to the satellite borne computer, and setting a closed loop test initial state of the satellite borne computer; receiving and displaying telemetering information of the satellite-borne computer;

a ground dynamics parameter setting computer: setting initial measurement values of the distance and the speed of the distance and speed measuring sensor; the initial measurement value can be data of the distance and speed measuring sensor during normal work, and can also be fault data of the distance and speed measuring sensor when the related wave beam is in fault output with a constant value, output with random or constant error and unavailable output;

ground dynamics test equipment: sending the initial measurement values of the distance and the speed of the distance and speed measuring sensor to an echo simulator of the distance and speed measuring sensor; driving and updating state information of a detector dynamic model according to guidance control instruction information sent by the satellite-borne computer, simulating and generating measurement information of a detector inertia measurement unit for the satellite-borne computer to collect, and completing satellite-ground time synchronization; meanwhile, when the height of the detector from the surface of the extraterrestrial celestial body is smaller than the height allowed to be introduced by the distance and speed measuring sensor, generating a distance and speed measuring simulation measured value in real time and sending the distance and speed measuring simulation measured value to the distance and speed measuring sensor echo simulator for use;

distance measuring and speed measuring sensor echo simulator: forming a radio frequency echo signal by using the initial measurement values of the distance and the speed of the distance and speed measuring sensor for the distance and speed measuring sensor to collect, and calibrating and compensating the distance, speed and telemetering information of the distance and speed measuring sensor by using the distance calibration value and the speed calibration value of each wave beam of the distance and speed measuring sensor so that the difference between the measurement result of the distance and speed measuring sensor and the initial measurement values of the distance and the speed provided by the ground dynamics test equipment meets the measurement error requirement; when closed loop test is verified, point target data with an initial value of 0 is generated, after the height of a detector from the surface of the extraterrestrial celestial body is smaller than the height allowed to be introduced by the distance measurement and speed measurement sensor, distance measurement and speed measurement analog measurement values sent by ground dynamics test equipment are received, the distance and speed values of each wave beam are analyzed, converted and updated, meanwhile, frequency conversion and modulation processing are carried out on received analog wave beam numbers, wave form control words, radio frequency emission signals and reference clock signals, echo data are calculated in real time according to corresponding distance delay, point target echo modulation data containing the echo characteristics of the extraterrestrial body surface in the current period are generated, and after synchronous control signals are received, radio frequency echo signals of required wave beams are output to the distance measurement and speed measurement sensor in real time.

The closed-loop verification method of the distance measurement and speed measurement sensor for the landing of the extraterrestrial celestial body is characterized by comprising the following steps of: the method comprises a calibration step and a normal test step,

the calibration process comprises the following steps:

1) the ground dynamics parameter setting computer sets the distance and the speed of the distance and speed measuring sensor sent by the ground dynamics testing equipment as fixed measurement values;

2) the remote control and remote measurement computer injects an instruction into the spaceborne computer to enable the distance and speed measurement sensor to be in a full working state, then sends a single access instruction to obtain distance and speed measurement and remote measurement information, and determines the distance and speed calibration value of each wave beam by comparing the distance and speed measurement information with the fixed measurement value set by the ground dynamics parameter setting computer;

3) the distance and speed values are calibrated and compensated through the ranging and speed measuring sensor echo simulator, so that the difference between the measuring result of the ranging and speed measuring sensor and the distance and speed values provided by the ground dynamics testing equipment meets the requirement of measuring errors, and the ranging and speed measuring sensor echo simulator is calibrated;

the normal testing process comprises the following steps:

1) the satellite-borne computer starts operation according to the instruction information of the initial position, speed, attitude angle, attitude angular speed, satellite hour and the like injected by the remote control and remote measurement computer, and sends the remote measurement information to the remote control and remote measurement computer for display; the ground dynamics equipment starts the updating of ground dynamics according to the set initial position, speed, attitude angle, attitude angular speed and satellite-hour information, and completes satellite-ground time synchronization; the ground dynamics test equipment simulates and generates the measurement information of the inertia measurement unit for the satellite-borne computer to collect according to the detector state information of the dynamics simulation; when the height of the detector from the surface of the extraterrestrial celestial body is smaller than the height allowed to be introduced by the distance and speed measuring sensor, starting to send the distance and speed measuring simulation measured value and the effectiveness thereof to the distance and speed measuring sensor echo simulator for use in real time;

2) the method comprises the steps that a satellite-borne computer obtains measurement data of an inertial measurement unit to finish satellite-borne inertial navigation recursion, when the height of a detector from the surface of an extraterrestrial celestial body is smaller than the height allowed to be introduced by a distance and speed measurement sensor, distance measurement, speed measurement value and effectiveness and relative measurement time information of the distance and speed measurement sensor are obtained in each control period, and correction of the inertial navigation recursion data is finished in the same control period; simultaneously, the satellite-borne computer sends a guidance control instruction to the ground dynamics testing equipment to drive the ground detector dynamics model;

3) the distance and speed measuring sensor echo simulator works in a point target mode, after the operation is started, the echo simulator always plays back point target data with an initial value of 0, after the height of the detector from the surface of the extraterrestrial celestial body is smaller than the height allowed to be introduced by the distance and speed measuring sensor, the ground dynamics testing equipment sends a distance and speed measuring analog value and the effectiveness thereof to the echo simulator, and the echo simulator analyzes, converts and updates the distance and speed value of each wave beam; simultaneously, carrying out frequency conversion and modulation processing on the received analog wave beam number and waveform control words, radio frequency emission signals and reference clock signals sent by the distance and speed measuring sensor, calculating echo data in real time according to corresponding distance delay, generating point target echo modulation data with the echo characteristics of the surface of the extraterrestrial celestial body in the current period, and outputting radio frequency echo signals of required wave beams to the distance and speed measuring sensor in real time after receiving synchronous control signals of the distance and speed measuring sensor;

4) the distance and speed measuring sensor acquires and processes the received radio frequency echo signal sent by the echo simulator to obtain the current distance and speed measuring information, and returns the distance and speed measuring information obtained by processing when the spaceborne computer sends a data fetching instruction;

5) the ground dynamics test equipment receives guidance control instruction information of the spaceborne computer, realizes driving of a digital model of an actuating mechanism (such as a thruster), generates force and moment information for driving a dynamic body of the detector, realizes real-time updating of state information of the dynamically simulated detector, and further simulates and generates measurement information of the inertia measurement unit and distance and speed measurement simulation values and validity information of the distance and speed measurement simulation values sent to the distance and speed measurement sensor echo simulator according to the measurement characteristics and error characteristics of the inertia measurement unit and the distance and speed measurement sensor.

6) And repeating the steps 1) to 5), and carrying out continuous hardware-in-loop closed-loop test on the performance of the speed and distance measuring sensor until the test requirements are met.

Compared with the prior art, the invention has the advantages that: the invention provides a distance and speed measuring sensor closed-loop verification system and a method for landing of an extraterrestrial celestial body. In addition, the invention can also realize the fault simulation verification of the constant fault output, random or constant error output, unavailable output and the like of the beam measurement result in the closed-loop process by setting the distance measurement and speed measurement information of each beam by the ground dynamics parameter setting computer.

Drawings

Fig. 1 is a schematic diagram of the principle of the system and the information flow.

Detailed Description

As shown in fig. 1, the distance and speed measuring sensor closed-loop verification system for the landing of extraterrestrial celestial bodies provided by the invention comprises two parts, namely a star-end product and ground test equipment, wherein the star-end product comprises a star-mounted computer and a distance and speed measuring sensor, and the ground test equipment comprises a remote control and remote measurement computer, a ground dynamics parameter setting computer, ground dynamics test equipment and a distance and speed measuring sensor echo simulator. The functions of each part are as follows:

1) satellite-borne computer

The satellite-borne computer receives a control instruction of the remote control and remote measurement computer and sends the remote measurement information to the remote control and remote measurement computer for display; the method comprises the steps that an on-board computer obtains measurement data of an inertial measurement unit simulated by ground dynamics testing equipment through a ground inspection port, sends instructions such as periodic counting and time correction to a distance and speed measurement sensor through an RS422 serial port, obtains information such as distance measurement, speed measurement values and effectiveness and relative measurement time of the distance and speed measurement measured by the distance and speed measurement sensor, and then realizes correction of the inertial navigation measurement data through an inertial navigation and distance and speed measurement information robust fusion algorithm (reference document: rank of Wangdao, Limaden, Huangyu and the like, spacecraft multisource information fusion autonomous navigation technology [ M ]. Beijing university of science and engineering publishing, 2018) of the on-board computer. And then, the spaceborne computer sends guidance control instruction information to the ground dynamics testing equipment through the ground inspection port, so that the ground detector dynamics model is driven.

2) Distance-measuring and speed-measuring sensor

The distance and speed measuring sensor sends information such as a synchronous control signal, a reference clock signal, a radio frequency emission signal, a simulation beam number, a waveform control word and the like to the distance and speed measuring sensor echo simulator every period to enable the echo simulator to generate a required radio frequency echo signal, processes the received radio frequency echo signal to obtain current distance and speed measuring measurement information, and returns to process to obtain the distance and speed measuring measurement information when the spaceborne computer sends a fetching instruction.

3) Echo simulator of distance and speed measuring sensor

The distance measurement and speed measurement sensor echo simulator adopts a distance measurement and speed measurement simulation value and effectiveness sent by a UDP network protocol to a ground dynamics testing device, and also adopts a waveform control word (which is only needed to be provided when only a plurality of appointed wave beams are simulated in each period under the condition of multi-wave beams) and a received simulation wave beam number sent by the distance measurement and speed measurement sensor (which is only needed to be provided when different wave beams are adopted in different height sections), a radio frequency emission signal and a reference clock signal to carry out analysis conversion, frequency conversion and modulation processing, point target echo modulation data of the current period are generated in real time according to corresponding distance delay, and after a synchronous control signal of the distance measurement and speed measurement sensor is received, a radio frequency echo signal of the needed wave beam is output to the distance measurement and speed measurement sensor in real time.

4) Ground dynamics test equipment

The ground dynamics test equipment mainly completes dynamics simulation of the detector, digital simulation of an inertia measurement unit and an execution mechanism (such as a thruster) and the like.

And the ground dynamics test equipment simulates and generates the measurement information of the inertia measurement unit for the satellite-borne computer to collect according to the position, speed, attitude angle, attitude angular speed and other state information of the detector simulated by the dynamics software. And meanwhile, when the height of the detector from the surface of the extraterrestrial celestial body is smaller than the height allowed to be introduced by the distance and speed measuring sensor, the distance and speed measuring simulation measurement value and the effectiveness thereof are sent to the distance and speed measuring sensor echo simulator for use in real time through a UDP network. The ground dynamics test equipment also receives information such as a guidance control instruction of the spaceborne computer, realizes driving of a digital model of an execution mechanism (such as a thruster), further generates information such as force and moment for driving a dynamic body of the detector, and realizes updating of state information such as the position, the speed, the attitude angle and the attitude angular speed of the detector.

5) Ground dynamics parameter setting computer

Before the closed-loop test is started, the ground dynamics parameter setting computer can set the distance and the speed of the distance and speed measuring sensor sent by the ground dynamics test equipment as fixed measurement values, and the distance and the speed calibration values of all beams are determined by comparing the distance and speed measuring telemetering information of the distance and speed measuring sensor obtained by the spaceborne computer. And then, the distance and the speed are compensated through the ranging and speed measuring sensor echo simulator, so that the difference between the measuring result of the ranging and speed measuring sensor and the initial measuring value of the distance and the speed provided by the ground dynamics testing equipment meets the requirement of measuring errors. Meanwhile, the fault simulation of constant fault output, random or constant error output, unavailable output and the like of the beam measurement result in the closed-loop process can be realized by setting the distance measurement and speed measurement information of each beam.

6) Remote control and remote measuring computer

The remote control and remote measurement computer sends a remote control instruction to the satellite borne computer and sets the closed loop test initial state of the satellite borne computer; and receiving and displaying the telemetering information of the satellite borne computer.

The system of the invention has the following specific working process:

(1) closed loop test preparation

1) After the ground and the satellite parts of the verification system are sequentially and normally powered on and started, the ground dynamics parameter setting computer sets the distance and the speed of the distance and speed measuring sensor sent by the ground dynamics testing equipment to be fixed measurement values.

2) The spaceborne computer injects an instruction through the remote control and remote measurement computer to enable the distance and speed measurement sensor to be in a full working state, then sends a single data fetching instruction to obtain distance and speed measurement and remote measurement information, and determines the distance and speed calibration value of each wave beam through comparison with a fixed measurement value set by the ground dynamics parameter setting computer.

3) And completing the power-on restart of the ground test equipment and the star-end product, and calibrating and compensating the distance and speed values through the distance and speed measuring sensor echo simulator to ensure that the difference between the measurement result of the distance and speed measuring sensor and the distance and speed values provided by the ground dynamics test equipment meets the measurement error requirement, thereby completing the calibration of the distance and speed measuring sensor echo simulator.

4) If the distance measurement and speed measurement fault closed-loop test is carried out, the ground dynamics parameter setting computer sets the relevant wave beams of the distance measurement and speed measurement sensor to be fault simulation of constant fault output, random or constant error output, unavailable output and the like. After the fault simulation value is sent to the echo simulator through the UDP network, the echo simulator can output a radio frequency echo signal with a fault according to the setting for the distance measuring and speed measuring sensor to collect. If the fault test is not carried out, the setting is not carried out, and the ground dynamics test equipment is used for calculating the output ranging and speed measuring analog values and the effectiveness thereof in real time to be used as the input values of the ranging and speed measuring sensor echo simulator.

(2) Closed loop test procedure

1) After the ground and the on-board part of the verification system are sequentially and normally powered on to start and the calibration and compensation of the ranging and speed measuring sensor echo simulator are completed, the on-board computer starts to operate according to the instruction information such as the initial position, the speed, the attitude angle, the attitude angular speed, the star hour and the like injected by the remote control and remote measurement computer, and sends the remote measurement information to the remote control and remote measurement computer for display; the ground dynamics equipment starts the updating of ground dynamics according to the set initial position, speed, attitude angle, attitude angular speed and satellite-hour information, and completes satellite-ground time synchronization; and the ground dynamics test equipment simulates and generates the measurement information of the inertia measurement unit for the satellite-borne computer to collect according to the detector state information of the dynamics simulation. And meanwhile, when the height of the detector from the surface of the extraterrestrial celestial body is smaller than the height allowed to be introduced by the distance and speed measuring sensor, the distance and speed measuring simulation measurement value and the effectiveness thereof are sent to the distance and speed measuring sensor echo simulator for use in real time through a UDP network protocol.

2) The method comprises the steps that a satellite-borne computer obtains measurement data of an inertial measurement unit through a ground inspection port to finish satellite-borne inertial navigation recurrence, when the height of a detector from the surface of an earth external celestial body is smaller than the height allowed to be introduced by a distance measurement and speed measurement sensor, distance measurement and speed measurement values and effectiveness and relative measurement time information of the distance measurement and speed measurement sensor are obtained in each control period through an RS422 serial bus, and correction of inertial navigation recurrence data is achieved through an inertial navigation and distance measurement and speed measurement robust fusion algorithm on the satellite-borne computer in the same control period. Meanwhile, the spaceborne computer sends guidance control instruction information to the ground dynamics testing equipment through the ground inspection port, and the ground detector dynamics model is driven.

3) The echo simulator of the distance and speed measuring sensor works in a point target mode, after the operation is started, the echo simulator can always play back point target data, and the initial value is 0. After the height of the detector from the surface of the extraterrestrial celestial body is smaller than the height allowed to be introduced by the distance and speed measuring sensor, the ground dynamics testing equipment sends distance and speed measuring analog values and effectiveness thereof to the echo simulator by adopting a UDP (user Datagram protocol) protocol, and the echo simulator analyzes, converts and updates the distance and speed values of each wave beam. And simultaneously, carrying out frequency conversion and modulation processing on the received analog wave beam number and waveform control words, radio frequency emission signals and reference clock signals sent by the distance and speed measuring sensor, calculating echo data in real time according to corresponding distance delay, generating point target echo modulation data with the echo characteristics of the surface of the extraterrestrial celestial body in the current period, and outputting radio frequency echo signals of required wave beams to the distance and speed measuring sensor in real time after receiving synchronous control signals of the distance and speed measuring sensor. Meanwhile, the dynamics data received through the network are stored locally, and the time of receiving the data is marked when the dynamics data are stored. In order to meet the real-time simulation requirement, the data refresh rate of the radio frequency echo signal is not less than 20Hz, and the time delay is not more than 3 ms.

4) The distance and speed measuring sensor acquires and processes the received radio frequency echo signal sent by the echo simulator to obtain the current distance and speed measuring information, and returns the distance and speed measuring information obtained by processing when the spaceborne computer sends a data fetching instruction.

5) The ground dynamics test equipment receives information such as a guidance control instruction of the spaceborne computer, realizes driving of an actuating mechanism (such as a thruster) digital model, generates information such as force and moment for driving a dynamic body of the detector, realizes real-time updating of state information of the dynamically simulated detector, and further simulates and generates measurement information of the inertia measurement unit and distance and speed measurement simulation values and validity information of the distance and speed measurement simulation values sent to the distance and speed measurement sensor echo simulator according to measurement characteristics and error characteristics of the inertia measurement unit and the distance and speed measurement sensor.

6) And repeating the steps 1) to 5), and carrying out continuous hardware-in-loop closed-loop test on the performance of the speed and distance measuring sensor until the test requirements are met.

Those skilled in the art will appreciate that those matters not described in detail in the present specification are well known in the art.