Multi-sensor fusion air-ground identification method

Abstract

The invention belongs to the technical field of helicopter state recognition, and particularly relates to a multi-sensor fusion air-ground recognition method. A laser altimeter and an ultrasonic altimeter are mounted outside a left / right skin of a front belly of a helicopter body in a helicopter, and a laser altimeter and an ultrasonic altimeter are also mounted outside a left / right skin of a tail cant beam of the helicopter. Forming a left front laser altimeter / left front ultrasonic altimeter, a right front laser altimeter / right front ultrasonic altimeter, a left rear laser altimeter / left rear ultrasonic altimeter and a right rear laser altimeter / right rear ultrasonic altimeter; and according to the measured values of the laser altimeter and the ultrasonic altimeter, and the left front wheel load switch signal, the right front wheel load switch signal, the left rear wheel load switch signal and the right rear wheel load switch signal, the air-ground state identification of the helicopter is realized.

Description

Technical Field

[0001] The invention belongs to the technical field of helicopter state recognition, and in particular relates to an air-to-ground recognition method based on multi-sensor fusion. Background Art

[0002] The original flight control system determines whether the helicopter is in the air or on the ground by simply relying on a wheel-borne signal, or by comprehensively judging the left front, right front, left rear, and right rear wheel-borne signals to identify the air-ground status, which can no longer meet the requirements of accurately identifying the air-ground status. Summary of the invention

[0003] The technical problem solved by the present invention is as follows: by installing a plurality of height measuring sensors at the wheels of a helicopter respectively, combining the wheel-borne signals of the left, right and rear tail wheels, the air-ground signal fusion of multiple sensors is realized, and the current state is judged in real time by integrating the switch quantity and the height value, so as to achieve high reliability and high safety of air-ground recognition and meet the requirements of air-ground mode recognition of the automatic take-off and landing function.

[0004] The technical solution of the present invention:

[0005] A multi-sensor fusion air-ground identification method, wherein a laser altimeter and an ultrasonic altimeter are installed on the left / right skin exterior of the front belly of a helicopter fuselage, and a laser altimeter and an ultrasonic altimeter are also installed on the left / right skin exterior of a helicopter tail beam, forming a left front laser altimeter / left front ultrasonic altimeter, a right front laser altimeter / right front ultrasonic altimeter, a left rear laser altimeter / left rear ultrasonic altimeter, and a right rear laser altimeter / right rear ultrasonic altimeter;

[0006] The air-to-ground state of the helicopter is identified according to the measured values ​​of the laser altimeter and the ultrasonic altimeter, and the left front, right front, left rear and right rear wheel-mounted switch signals.

[0007] Furthermore,

[0008] When the left wheel clearance state is empty, if two of the following three conditions are met, the left wheel clearance state changes to ground; the three conditions are:

[0009] The left wheel-borne signal is ground; the left front laser measurement height is less than the first preset threshold; the left rear ultrasonic measurement height threshold is less than the second preset threshold.

[0010] Furthermore,

[0011] When the left wheel clearance state is ground, if two of the following three conditions are met, the left wheel clearance state becomes empty; the three conditions are:

[0012] The left wheel signal is empty; the left front laser measurement height is greater than the first preset threshold; the left rear ultrasonic measurement height threshold is greater than the second preset threshold.

[0013] Furthermore,

[0014] When the right wheel clearance state is empty, if two of the following three conditions are met, the right wheel clearance state changes to ground; the three conditions are:

[0015] The right wheel load signal is ground; the right front laser measurement height is less than the first preset threshold; the right rear ultrasonic measurement height threshold is less than the second preset threshold.

[0016] Furthermore,

[0017] When the right wheel clearance state is ground, if two of the following three conditions are met, the right wheel clearance state changes to empty; the three conditions are:

[0018] The right wheel load signal is empty; the right front laser measurement height is greater than the first preset threshold; the right rear ultrasonic measurement height threshold is greater than the second preset threshold.

[0019] Furthermore,

[0020] When the tail engine wheel open ground state is empty, if four of the following six conditions are met, the tail engine wheel open ground state is ground; the six conditions are:

[0021] The left rear wheel load signal is ground; the right rear wheel load signal is ground; the right rear laser measurement height is less than the first threshold; the left rear laser measurement height is less than the first threshold; the right rear ultrasonic measurement height is less than the second threshold; the left rear ultrasonic measurement height is less than the second threshold.

[0022] Furthermore,

[0023] When the tail engine wheel well ground state is ground, if four of the following six conditions are met, the tail engine wheel well ground state is empty; the six conditions are:

[0024] The left rear wheel load signal is empty; the right rear wheel load signal is empty; the right rear laser measurement height is greater than the first threshold; the left rear laser measurement height is greater than the first threshold; the right rear ultrasonic measurement height is greater than the second threshold; the left rear ultrasonic measurement height is greater than the second threshold.

[0025] Furthermore,

[0026] The left wheel lift-off signal, right wheel lift-off signal and tail wheel lift-off signal are used to judge the wheel lift-off status during automatic take-off and landing. The tail wheel leaves the ground last during take-off and touches the ground first during landing. The tail wheel lift-off signal is used as the final helicopter ground status.

[0027] The technical solution of the present invention realizes a highly reliable, high-precision, and high-safety air-ground identification method and a smooth switching between two states through multi-sensor signal fusion. The method has been successfully applied to the air-ground judgment of a certain type of helicopter automatic take-off and landing technology. Test flights have shown that the method is safe and reliable and has high promotion and practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the process of judging the state of the rear wheel being clear of land;

[0029] Figure 2 Schematic diagram of the left / right wheel clearance status judgment process. DETAILED DESCRIPTION

[0030] The technical solution of the present invention is described in detail below with reference to the accompanying drawings.

[0031] The technical solution of the present invention installs a laser altimeter and an ultrasonic altimeter that can detect the height of the helicopter above the ground when it is at low altitude or close to the ground, and integrates the wheel-mounted switch signal to realize air-ground status recognition, thereby ensuring accurate air-ground status recognition of the automatic take-off and landing function and improving the autonomous flight capability of the helicopter.

[0032] By installing ultrasonic altimeters and laser altimeters on the helicopter wheels, the altitude signal and wheel load signal are integrated to achieve the recognition of air-to-ground mode. The research on air-to-ground recognition technology is as follows:

[0033] (a) The height of the helicopter from the ground when it is at low altitude or close to the ground is detected by using a laser altimeter or ultrasonic altimeter; they are installed on the left / right skin outside the front belly of the helicopter fuselage and the left / right skin outside the tail beam, forming a left front laser altimeter / left front ultrasonic altimeter, a right front laser altimeter / right front ultrasonic altimeter, a left rear laser altimeter / left rear ultrasonic altimeter, and a right rear laser altimeter / right rear ultrasonic altimeter;

[0034] (b) Combine the altitude measurements of four laser altimeters and four ultrasonic altimeters with the left front, right front, left rear, and right rear wheel switch signals to design a multi-sensor space-to-ground recognition method;

[0035] (c) Combine the switch signal and altitude signal of the wheel-mounted switch to design air-to-ground mode recognition technology and smooth air-to-ground mode conversion, automatically realize air-to-ground state conversion, and meet the automatic take-off and landing function requirements of the flight control system.

[0036] Specifically,

[0037] By making full use of the characteristics of sensor signals and combining the redundant sensor to measure height and wheel load switch signals, the identification of the open-ground state and the smooth transition of the state can be achieved.

[0038] The flight control system collects the left front, right front, left rear, and right rear wheel switch signals. In addition, in order to improve the measurement accuracy of the relative height signal and the reliability of the air-ground judgment logic, four laser altimeters and four ultrasonic altimeters are installed on the helicopter to construct a multi-altimeter measurement solution;

[0039] For the left wheel: perform three-judgment and two-synthesis on the ultrasonic altimeter, laser altimeter and wheel-load signal to form a left wheel lift-off signal; Figure 2 shown.

[0040] When the left wheel clearance state is empty, if two of the following three conditions are met, the left wheel clearance state changes to ground; the three conditions are:

[0041] The left wheel carrier signal is ground; the left front laser measurement height is less than the first preset threshold; the left rear ultrasonic measurement height threshold is less than the second preset threshold;

[0042] When the left wheel clearance state is ground, if two of the following three conditions are met, the left wheel clearance state becomes empty; the three conditions are:

[0043] The left wheel signal is empty; the left front laser measurement height is greater than the first preset threshold; the left rear ultrasonic measurement height threshold is greater than the second preset threshold;

[0044] For the right wheel: perform three-judgment and two-synthesis on the ultrasonic altimeter, laser altimeter and wheel load signal to form the right wheel lift-off signal; Figure 2 shown.

[0045] When the right wheel clearance state is empty, if two of the following three conditions are met, the right wheel clearance state changes to ground; the three conditions are:

[0046] The right wheel load signal is ground; the right front laser measurement height is less than the first preset threshold; the right rear ultrasonic measurement height threshold is less than the second preset threshold;

[0047] When the right wheel clearance state is ground, if two of the following three conditions are met, the right wheel clearance state changes to empty; the three conditions are:

[0048] The right wheel load signal is empty; the right front laser measurement height is greater than the first preset threshold; the right rear ultrasonic measurement height threshold is greater than the second preset threshold;

[0049] For the tail wheel: six judgments and four comprehensive processing are performed based on the two ultrasonic height thresholds, two laser altimeter height thresholds and the left and right rear tail wheel load signals to form the tail wheel lift-off signal; Figure 1 shown.

[0050] When the tail engine wheel open ground state is empty, if four of the following six conditions are met, the tail engine wheel open ground state is ground; the six conditions are:

[0051] The left rear wheel load signal is ground; the right rear wheel load signal is ground; the right rear laser measurement height is less than the first threshold; the left rear laser measurement height is less than the first threshold; the right rear ultrasonic measurement height is less than the second threshold; the left rear ultrasonic measurement height is less than the second threshold.

[0052] When the tail engine wheel well ground state is ground, if four of the following six conditions are met, the tail engine wheel well ground state is empty; the six conditions are:

[0053] The left rear wheel load signal is empty; the right rear wheel load signal is empty; the right rear laser measurement height is greater than the first threshold; the left rear laser measurement height is greater than the first threshold; the right rear ultrasonic measurement height is greater than the second threshold; the left rear ultrasonic measurement height is greater than the second threshold.

[0054] The left wheel lift-off signal, right wheel lift-off signal and tail wheel lift-off signal can be used to judge the wheel lift-off status during automatic take-off and landing. The tail wheel leaves the ground last during take-off and touches the ground first during landing, so the tail wheel lift-off signal is used as the final ground status.

[0055] Through the research of the present invention, a highly reliable, high-precision, and high-safety air-ground identification method and a smooth switching between two states are realized through multi-sensor signal fusion. The method has been successfully applied to the air-ground judgment of a certain type of helicopter automatic take-off and landing technology. The test flight shows that the method is safe and reliable and has high promotion and practical value.

Claims

1. A multi-sensor fusion space-ground recognition method, characterized in that: In the helicopter, a laser altimeter and an ultrasonic altimeter are installed on the outside of the left / right skin of the front belly of the fuselage, and a laser altimeter and an ultrasonic altimeter are also installed on the outside of the left / right skin of the helicopter tail beam, forming a left front laser altimeter / left front ultrasonic altimeter, a right front laser altimeter / right front ultrasonic altimeter, a left rear laser altimeter / left rear ultrasonic altimeter, and a right rear laser altimeter / right rear ultrasonic altimeter; The air-to-ground state of the helicopter is identified according to the measured values ​​of the laser altimeter and the ultrasonic altimeter, and the left front, right front, left rear and right rear wheel-mounted switch signals.

2. The multi-sensor fusion space-ground recognition method according to claim 1 is characterized in that: When the left wheel clearance state is empty, if two of the following three conditions are met, the left wheel clearance state changes to ground; the three conditions are: The left wheel-borne signal is ground; the left front laser measurement height is less than the first preset threshold; the left rear ultrasonic measurement height threshold is less than the second preset threshold.

3. The multi-sensor fusion space-ground recognition method according to claim 1, characterized in that: When the left wheel clearance state is ground, if two of the following three conditions are met, the left wheel clearance state becomes empty; the three conditions are: The left wheel signal is empty; the left front laser measurement height is greater than the first preset threshold; the left rear ultrasonic measurement height threshold is greater than the second preset threshold.

4. The multi-sensor fusion space-ground recognition method according to claim 1, characterized in that: When the right wheel clearance state is empty, if two of the following three conditions are met, the right wheel clearance state changes to ground; the three conditions are: The right wheel load signal is ground; the right front laser measurement height is less than the first preset threshold; the right rear ultrasonic measurement height threshold is less than the second preset threshold.

5. The multi-sensor fusion space-ground recognition method according to claim 1, characterized in that: When the right wheel clearance state is ground, if two of the following three conditions are met, the right wheel clearance state changes to empty; the three conditions are: The right wheel load signal is empty; the right front laser measurement height is greater than the first preset threshold; the right rear ultrasonic measurement height threshold is greater than the second preset threshold.

6. The multi-sensor fusion space-ground recognition method according to claim 1 is characterized in that: When the tail engine wheel open ground state is empty, if four of the following six conditions are met, the tail engine wheel open ground state is ground; the six conditions are: The left rear wheel load signal is ground; the right rear wheel load signal is ground; the right rear laser measurement height is less than the first threshold; the left rear laser measurement height is less than the first threshold; the right rear ultrasonic measurement height is less than the second threshold; the left rear ultrasonic measurement height is less than the second threshold.

7. The multi-sensor fusion space-ground recognition method according to claim 1, characterized in that: When the tail engine wheel well ground state is ground, if four of the following six conditions are met, the tail engine wheel well ground state is empty; the six conditions are: The left rear wheel load signal is empty; the right rear wheel load signal is empty; the right rear laser measurement height is greater than the first threshold; the left rear laser measurement height is greater than the first threshold; the right rear ultrasonic measurement height is greater than the second threshold; the left rear ultrasonic measurement height is greater than the second threshold.

8. The multi-sensor fusion space-ground recognition method according to claim 1, characterized in that: The left wheel lift-off signal, right wheel lift-off signal and tail wheel lift-off signal are used to judge the wheel lift-off status during automatic take-off and landing. The tail wheel leaves the ground last during take-off and touches the ground first during landing. The tail wheel lift-off signal is used as the final helicopter ground status.

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