Air cushion vehicle propeller pitch angle offset correction method

Abstract

A kind of air cushion vehicle propelling pitch angle deviation correction method, air propeller and pitch feedback value maximum allowed angle difference are set, air propeller angle θ 1And pitch feedback value angle θ 2, calculate air propeller and pitch feedback value angle difference θ α ; obtain the angle deviation when resolver decoder is zeroed θ 3;According to the characteristics of engine and propeller matching, the corrected air propeller and pitch feedback value allowed deviation angle difference is obtained;When pitch variable pitch instruction is carried out, according to the characteristics of engine and propeller matching, the rotating speed of propeller under different pitch is worked.According to the sudden change of engine working condition, after shutdown, the angle difference between air propeller and pitch feedback value is checked θ α And the relationship between pitch angle is judged whether it needs to be corrected;If| θ α |>||then stop pitch action, carry out pitch angle deviation correction;If| θ α |≤||, according to the characteristics of engine and propeller matching, air propeller continues to act, to ensure the safety of navigation.

Description

Technical Field

[0001] This invention relates to the field of hovercraft technology, and in particular to a method for correcting the pitch angle deviation of hovercraft propulsion. Background Technology

[0002] Hovercraft typically consist of three propellers: left, center, and right. Powered by the main propulsion engine, these propellers rotate at high speed. By controlling the pitch, the propeller load is altered, thus propelling the hovercraft forward. The hovercraft's forward movement and steering are achieved by adjusting the propeller blade angle and varying the airflow rate and direction entering the propeller system. However, if the propeller pitch angle deviates significantly from the feedback value, the operator cannot discern the true propeller angle from the feedback, affecting the hovercraft's attitude and posing a significant threat to navigation safety. Summary of the Invention

[0003] In response to the shortcomings of the existing production technology, the applicant provides a method for correcting the pitch angle deviation of the propulsion screw of a hovercraft, which can effectively solve the problems existing in the prior art, ensure safety, and greatly improve the safety factor.

[0004] The technical solution adopted in this invention is as follows: A method for correcting the propulsion pitch angle deviation of a hovercraft includes the following steps: Step 1: Set the maximum allowable angle difference between the air propeller and pitch feedback value. ; Step 2: Obtain the air propeller angle i 1 and pitch feedback value angle i 2; Step 3: Obtain the angle deviation when the rotary transformer decoder is set to zero. i 3; Step 4: Calculate the angle difference between the air propeller and the pitch feedback value. i α ; Step 5: Based on the propeller matching characteristics, obtain the corrected air propeller and pitch feedback value allowable deviation angle difference. ; Step 6: If the gas turbine operating conditions change abruptly, check the angle difference between the air propeller and the pitch feedback value. i α and The relationship between these factors determines whether the pitch angle needs correction. Step 7: If | i α |>| |Then stop the pitch action and perform pitch angle offset correction; such as| i α |≤| |, then the air propeller is controlled to continue operating based on the propeller matching characteristics; Step 8: Determine if the pitch is in place; otherwise, repeat steps 2 through 7.

[0005] Its further technical solution lies in: Set the initial pitch and the maximum allowable angle difference. =1°.

[0006] Corrected allowable angle difference Less than or equal to the maximum permissible angle difference of the initial pitch .

[0007] The propulsion pitch angle range is -28° to +48°.

[0008] When the propulsion pitch is being adjusted, if a sudden change occurs in the gas turbine's operating conditions, the air propeller and the pitch feedback value angle difference should be checked after shutdown. i α and The relationship between the pitch angle and the pitch angle determines whether correction is needed. The method for determining this is as follows: If | i α |>| Then stop the pitch operation and correct the pitch angle offset by setting the resolver decoder to zero.

[0009] The specific process is as follows: Due to the angle deviation when the rotary transformer decoder is set to zero... i 3， Adjust the air propeller angle to ± i 3°, at this point the pitch feedback value angle is adjusted to ( i 2- i 1+(± i 3) Short-circuit the zero-position terminal on the rotary transformer decoder to reset; if the resetting is complete... i α |≤| If the result is correct, the pitch angle offset correction is successfully completed; otherwise, repeat the above operation.

[0010] The beneficial effects of this invention are as follows: This invention determines whether the pitch angle needs correction by measuring the propeller angle difference, which can effectively prevent the hovercraft's navigation attitude from being affected by excessive angle difference, and is of great significance in ensuring the safe navigation of hovercraft.

[0011] Furthermore, adjustments are very convenient. When adjusting the propulsion pitch, if a sudden change occurs in the gas turbine's operating conditions, the angle difference between the air propeller and the pitch feedback value can be checked after shutdown. i α and The relationship between these factors determines whether the pitch angle needs correction.

[0012] If | i α |>| Then stop the pitch operation and correct the pitch angle offset by setting the resolver decoder to zero.

[0013] Due to the angle deviation when the rotary transformer decoder is set to zero. i 3. Adjust the air propeller angle to ± i 3°, at this point the pitch feedback value angle is adjusted to ( i 2- i 1+(± i 3) Short-circuit the zero-position terminal on the rotary transformer decoder to reset; if the resetting is complete... i α |≤| If the result is correct, the pitch angle offset correction is successfully completed; otherwise, repeat the above operation. Attached Figure Description

[0014] Figure 1 This is a block diagram of the propulsion pitch structure of the hovercraft of the present invention.

[0015] Figure 2 This is a flowchart of the method for correcting the pitch angle deviation of the air-cushioned vehicle propulsion system according to the present invention. Detailed Implementation

[0016] The specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0017] like Figure 1 and Figure 2 The method for correcting the pitch angle deviation of a hovercraft propulsion system described in this embodiment includes the following steps: Step 1: Set the maximum allowable angle difference between the air propeller and pitch feedback value. ; Step 2: Obtain the air propeller angle i 1 and pitch feedback value angle i 2; Step 3: Obtain the angle deviation when the rotary transformer decoder is set to zero. i 3; Step 4: Calculate the angle difference between the air propeller and the pitch feedback value. i α ; Step 5: Based on the propeller matching characteristics, obtain the corrected air propeller and pitch feedback value allowable deviation angle difference. ; Step 6: If the gas turbine operating conditions change abruptly, check the angle difference between the air propeller and the pitch feedback value. iα and The relationship between these factors determines whether the pitch angle needs correction. Step 7: If | i α |>| Then stop the pitch action and perform pitch angle offset correction; For example | i α |≤| |, then the air propeller is controlled to continue operating based on the propeller matching characteristics; Step 8: Determine if the pitch is in place; otherwise, repeat steps 2 through 7.

[0018] Set the initial pitch and the maximum allowable angle difference. =1°.

[0019] Corrected allowable angle difference Less than or equal to the maximum permissible angle difference of the initial pitch .

[0020] The propulsion pitch angle range is -28° to +48°.

[0021] When the propulsion pitch is being adjusted, if a sudden change occurs in the gas turbine's operating conditions, the air propeller and the pitch feedback value angle difference should be checked after shutdown. i α and The relationship between the pitch angle and the pitch angle determines whether correction is needed. The method for determining this is as follows: If | i α |>| Then stop the pitch operation and correct the pitch angle offset by setting the resolver decoder to zero.

[0022] The specific process is as follows: Due to the angle deviation when the rotary transformer decoder is set to zero... i 3. Adjust the air propeller angle to ± i 3°, at this point the pitch feedback value angle is adjusted to ( i 2- i 1+(± i 3) Short-circuit the zero-position terminal on the rotary transformer decoder to reset; if the resetting is complete... i α |≤| If the result is correct, the pitch angle offset correction is successfully completed; otherwise, repeat the above operation.

[0023] This embodiment provides a method for correcting the propulsion pitch angle deviation of a hovercraft, such as... Figure 2 As shown, it includes the following steps: Example: During the navigation of the hovercraft, the operating value of the No. 2 propulsion gas turbine suddenly changed. When the engine was stopped for inspection, it was found that the angle deviation between the No. 2 air propeller and the pitch feedback value was too large.

[0024] Step 1: According to the control system logic instructions, the maximum allowable angle difference between the air propeller and the pitch feedback value is specified to be 1°.

[0025] Step two: The measured air propeller angle is 30°, and the pitch feedback angle is 25°.

[0026] Step 3: After testing, it was found that the angle of the rotary transformer decoder when it was set to zero was -0.5°.

[0027] Step four: Based on the propeller matching characteristics, obtain the corrected air propeller and pitch feedback value with an allowable deviation angle difference of 0.5°.

[0028] Step 5: After inspection, the angle difference between the air propeller and the pitch feedback value is 5°, which is greater than the allowable deviation angle difference of 0.5°. Therefore, the pitch angle needs to be corrected.

[0029] Step six: Since the rotary transformer decoder has a 0.5° angular deviation, it cannot accurately adjust the actuator to the zero pitch value when set to zero position. Therefore, the air propeller angle is adjusted to -0.5°. At this time, the pitch feedback value angle is adjusted to (25-30+(-0.5))°.

[0030] Step 7: Short-circuit the zero-position terminal on the rotary transformer decoder to reset the pitch feedback value. The resulting angle value is -0.5°, consistent with the angle of the air propeller. At this point | i α |=0≤| | Complete the correction. If there is still a certain deviation after setting, repeat the above operation.

[0031] The above description is an explanation of the present invention and not a limitation thereof. The scope of the present invention is defined by the claims. Within the scope of protection of the present invention, any form of modification may be made.

Claims

1. A method for correcting the propulsion pitch angle deviation of a hovercraft, characterized in that: The following steps are included: Step 1: Set the maximum allowable angle difference between the air propeller and pitch feedback value. ; Step 2: Obtain the air propeller angle θ 1 and pitch feedback value angle θ 2; Step 3: Obtain the angle deviation when the rotary transformer decoder is set to zero. θ 3; Step 4: Calculate the angle difference between the air propeller and the pitch feedback value. θ α ; Step 5: Based on the propeller matching characteristics, obtain the corrected air propeller and pitch feedback value allowable deviation angle difference. ; Step 6: If the gas turbine operating conditions change abruptly, check the angle difference between the air propeller and the pitch feedback value. θ α and The relationship between these factors determines whether the pitch angle needs correction. Step 7: If | θ α |>| Then, the pitch action is stopped, pitch angle offset correction is performed, and the pitch angle offset correction is performed by setting the resolver decoder to zero; for example, | θ α |≤| |, then the air propeller is controlled to continue operating based on the propeller matching characteristics; Step 8: Determine if the pitch is in place; otherwise, repeat steps 2 through 7. The specific process for correcting pitch angle offset by setting the rotary transformer decoder to zero is as follows: due to the angle deviation when the rotary transformer decoder is set to zero... θ 3， Adjust the air propeller angle to ± θ 3°, at this point the pitch feedback value angle is adjusted to ( θ 2- θ 1+(± θ 3) Short-circuit the zero-position terminal on the rotary transformer decoder to reset it; if the resetting is complete... θ α |≤| If the result is positive, the pitch angle offset correction is successfully completed; otherwise, repeat the above operation.

2. The method for correcting the propulsion pitch angle deviation of a hovercraft as described in claim 1, characterized in that: Set the initial maximum allowable angle difference. =1°.

3. The method for correcting the propulsion pitch angle deviation of a hovercraft as described in claim 2, characterized in that: Corrected allowable deviation angle difference Less than or equal to the initial maximum permissible angle difference .

4. The method for correcting the propulsion pitch angle deviation of a hovercraft as described in claim 1, characterized in that: The propulsion pitch angle range is -28° to +48°.

Images